Air pollution alert issued for Mon Valley extended; those with respiratory problems vulnerable

An air pollution watch for the Mon Valley issued for Wednesday has now been extended through all of Thursday, when forecast conditions indicate that tiny particles known as PM2.5 will likely exceed the 24-hour standard.

Allegheny County says young children, seniors and those with respiratory problems, such as asthma, emphysema, and bronchitis, are especially vulnerable to the effects of air pollution and should limit outdoor activities during this time.

Additionally, the Pennsylvania Department of Environmental Protection has declared another Air Quality Action Day for Thursday by issuing a code orange for the LibertyClairton area.

A strong weather inversion with light winds will permit fine particle matter pollution (PM2.5) to build overnight into Thursday morning. The highest PM2.5 concentrations will come between 3 and 11 a.m.

A similar “episode” occurred under similar weather conditions from Oct. 22 to 26, which brought expressions of concern from environmental groups at the county Health Department’s meeting this month.